by David Potter
Diocletian’s decision to govern away from Rome was accompanied by a gradual, but thorough, reshuffling of the way in which government was organized. The tradition of dividing offices according to social class had largely ended in the middle of the third century. Most offices were now in the hands of men who, though technically equestrians, had little in common with the officials of the Antonine age. The hyperinflation that resulted from Aurelian’s currency reform meant that the traditionally high salaries of these officers were now relatively modest. Although the annual pay of a legionary had been set at 1250 denarii in the period after Caracalla’s reign, a lower-level equestrian, whose salary had not been increased, now made just 20 times the salary of a humble infantryman, as opposed to 60 times in the second century. The property valuations that had defined the equestrian and senatorial order in the Augustan age were likewise now meaningless. These changes had a levelling effect, placing the imperial office within the reach of men who would, in the past, have remained local dignitaries or have had little prospect of advancing beyond the level of a unit commander. People who disliked Diocletian would claim that he was little better than a barbarian of peasant background. This accusation, though false, reflects the fact that government was no longer the preserve of multimillionaires who would now have felt distinctly uncomfortable taking orders from people who were so unlike themselves.
The new civil administration had four main elements. Provincial governors reported through the praetorian prefects, and were henceforth to be responsible only for the administration of justice and the delivery of taxes in produce. The office of the res privata, the descendant of the old patrimonium, took over responsibility for the collection of all taxes paid in coin, the output from mines and the minting of coins. The equestrian secretariats of the old empire were now subsumed, along with the legal staff, under the authority of the magister officiorum, master of offices, while the operations of the various palaces continued to be under the control of cubicularii, now more numerous than ever before and more likely to be eunuchs.
Birth of the Tetrarchy
For the present, the army was under the direct command of each Augustus, with comites or duces commanding larger formations. The most momentous change in the system, however, came about as a result of a series of major setbacks suffered by Maximian in attempting to suppress a revolt that broke out along the Rhine and in Britain under Carausius, formerly the senior commander in the area.
Carausius’ rebellion began in AD 288, but within three years Maximian had driven his forces out of most of northern Gaul. However, when he attempted to capitalize on this success by invading Britain, his fleet was destroyed in a storm. Carausius took advantage of this disaster to reoccupy parts of the Gaulish mainland. In AD 293 Maximian, whose authority was threatened by the difficulties he was experiencing, appointed a deputy emperor to take charge of the campaign. Diocletian followed suit, on the understanding that the two deputies, or Caesars, would one day succeed the current Augusti. This refined system of rule was known as the Tetrarchy (‘rule of four’). The new Caesars were Flavius Constantius (c. AD 250–306) and Gaius Galerius Valerius Maximianus (known simply in English as Galerius; c. AD 250–311). Both Constantius and Galerius were experienced soldiers, and their appointments relieved the Augusti of the need to take personal control of potentially risky military operations. To celebrate their new offices, the two men married into the families of their patrons: Constantius married Theodora, daughter of Maximian, while Galerius took Valeria, daughter of Diocletian, as his wife.
At the time of his promotion to the rank of Caesar, Constantius had one son by a woman named Helena – according to nasty gossip, a barmaid from the Balkans, though in fact she was a respectable woman from Drepanum in western Turkey – whom he continued to support. This son, whose name was Constantine, was around 11 years old in AD 293. A few years later he would serve in Diocletian’s court, where he would ultimately be joined by Maximian’s slightly younger son, Maxentius (c. AD 278–312). In time, both would become emperors.
Constantius soon proved his worth, driving Carausius’ forces out of Gaul, invading Britain and bringing the breakaway state back under central government control. Galerius’ record was initially more chequered. After years of internal turmoil, the Sassanian regime had recovered its sense of purpose under the leadership of Shapur I’s son Narseh (r. AD 293–302), who had seized the throne in a coup d’état in AD 293. Narseh took great exception to Roman support for the restoration of an Arsacid ruler in parts of Armenia. In AD 297 he invaded Armenia and, pushing south, inflicted a serious defeat on Galerius, who had been lured into giving battle around Carrhae, which now had the unique distinction of being the only city to witness three major Roman defeats.
Diocletian was less than impressed with Galerius’ performance. He came in person to Antioch, where he made Galerius march before his chariot for more than a mile before the assembled army, a powerful statement that emperors were responsible for military failure. Of more practical value was a new plan of campaign that drew Narseh into the Armenian mountains, where Galerius was able to win a decisive victory in AD 298, forcing the Persians to surrender five provinces east of the Tigris, and, with them, direct access to the Armenian highlands. It was perhaps the greatest victory won by a Roman army since the time of Marcus Aurelius.
The strength of the new collegial system of government was further demonstrated, even as Galerius advanced against Narseh, by the fact that Diocletian and Maximian were able to direct their energies towards quelling local disturbances in Egypt and Spain, while Constantius set up his headquarters at Trier to launch repeated assaults against the Franks, a loose federation of Germanic tribes along the Lower Rhine, and the Alamanni in southern Germany. It was with some justice that the propagandists of the regime trumpeted the restoration of the Roman world. It was also at this time that Diocletian turned his attention to domestic policy.
Domestic reforms
Throughout the AD 280s and 290s a pair of jurists named Gregorius and Hermogenianus had tried to systematize the huge corpus of Roman law. In AD 291 Gregorius produced a collection of the legal opinions of previous emperors that were still regarded as valid sources of law, while Hermogenianus updated the collection in AD 298 to include the rulings of Diocletian. The urge to set the legal record straight was just one part of a concerted effort to change the way in which the reformed imperial administration governed its subjects. In AD 296 Diocletian introduced a new tax system that aimed to create a coherent definition of the taxable units for the basic taxes across all the provinces (this reform is thought to have caused the revolts that engaged the two Augusti while Galerius was defeating the Persians). Prompted chiefly by complaints from the army about the dwindling purchasing power of their salaries, in AD 301 the emperor introduced a new system of coinage, followed by an edict fixing maximum prices for goods and services throughout the empire. The effort was a failure, but, like Diocletian’s other fiscal measures, demonstrated his conviction that the government could reform the conduct of the empire’s subjects to make them more efficient servants of the regime. Crucial to all of this was the view that the emperor no longer existed to serve the state but rather that the state, having been saved from its enemies, should serve the emperor.
By the end of AD 301, Diocletian had survived longer than any emperor since Septimius Severus, but he was also in his sixties. What would happen next? Diocletian was giving very clear indications that he did not intend to die in office; he had constructed a grand palace at Spalatum (Split), near his homeland of Salonae in modern Croatia, to which he intended to retire. But what of Maximian, and what of the Caesars? Constantius, who had been appointed a few weeks before Galerius, would naturally succeed to the position of Augustus that Diocletian intended to vacate, while Galerius might be expected to wait until Maximian, who had been in power for one year less than Diocletian, decided that it was time for him to leave as well. Long-term plans for the succession seem in any event to have bee
n unformed. Who would be the next Caesars? In answering this question the key factor may have been a shortage of male children on the eastern side: Diocletian had only a daughter, and Galerius’ son, Candidianus, was the child of his first marriage (nasty rumour held that he was actually the son of a concubine and thus illegitimate). Constantius and Maximian both had sons; Constantius had several, in fact, though the oldest, Constantine, was also the product of an earlier marriage. By 300, when Constantine was married to a woman whose parents were not members of the imperial college, a decision seems to have been made that the new Caesars would not be blood relatives of the existing ones (though they might be connected by marriage). As time passed, relations between the eastern and western courts grew strained. Diocletian had not seen Maximian in more than a decade, and there is no evidence that he had ever met Constantius as Caesar. Moreover, neither of the western emperors enforced the edict on maximum prices, which they may rightly have regarded as wholly unworkable.
A late spasm of persecution
On 24 February, AD 303, Diocletian introduced a further strain into the relationship between east and west. It was on this day that he posted an edict at Nicomedia ordering all Christians to sacrifice to the traditional gods. Their communal property was seized, and those who refused to recant their faith faced the loss of their civil rights and even capital punishment. It was now more than forty years since Gallienus had brought the persecution instituted by his father to an end, and some 30 years since Aurelian had referred the decision of a dispute among the Christians of Antioch to the bishops of Italy – and the question of the relationship between Christians and non-Christians in the empire had ceased to be a burning issue. By this stage, Christians were well represented in the army and the court. Most significantly, many were also employed in the higher-education establishment at Nicomedia, where the seminal early Christian teacher Lactantius (c. AD 240–320) may first have met Constantine.
The result of Diocletian’s edict was to fuel the fire of Christian fundamentalism in some areas and alienate men like Lactantius. The rationale behind the edict, which upset long-established relationships, is hard to fathom. The fact that the edict ceased to be enforced within 18 months of its promulgation – only to be renewed with especial vigour by Galerius when he stepped into the role of Augustus – suggests indeed that Lactantius was right to explain it as a matter of politics more than of faith, and that the bigotry which was the driving force behind the measure was a particular hallmark of Galerius. Certainly, the responses of the Tetrarchs varied greatly; Constantius largely ignored the edict, while Maximian’s enforcement of it was less than enthusiastic. The measure served to highlight sharply differences between the eastern and western rulers on the very eve of an important journey that Diocletian planned to make to Rome in AD 304 to celebrate his and Maximian’s 20 years of shared power.
In ordering this joint celebration, Diocletian unilaterally took it upon himself to add a year to the period that Maximian had actually spent in office. At their meeting in Rome, Diocletian spelt out the intention behind his deliberate miscounting to his fellow senior member of the Tetrarchy: now that he and Maximian had the ‘same’ number of years in power, he expected them both to abdicate on the same day. Concurrently, he announced that he had already chosen the new Caesars, one of whom was a general named Flavius Valerius Severus (d. AD 307), and the other the nephew of Galerius, Maximinus Daia (c. AD 270–313). The principle enshrined in this pronouncement was that emperors made emperors; inheritance was not to be considered a decisive factor in the succession.
Renouncing the purple
Maximian and Constantius must have been infuriated by Diocletian’s decision, but there was little they could do about it. As was only fitting after a 20-year reign in which he had effectively restored Rome to a position of dominance not seen since the time of Septimius Severus, Diocletian’s personal authority was unbounded. Although not all of his actions could be regarded as prudent – the edicts on maximum prices and Christian persecution being cases in point – he possessed genuine wisdom. He was modest enough to realize that he could not govern on his own, and willing to entrust great power to a man (Constantius) who was plainly not part of his inner circle; and he was consistent enough in his belief that the nature of the imperial office needed to be changed that he did what no other emperor had ever dared do – he voluntarily renounced the most powerful position in the world.
On 1 May, AD 305, Diocletian removed the purple cloak that symbolized his authority and draped it around the shoulders of Maximinus Daia. Galerius ascended to the rank of Augustus at Sirmium. Maximian handed over power to Severus outside Milan, probably in the presence of Constantius, who now became the senior Augustus.
Withdrawing to his retirement palace, Diocletian spent his time growing cabbages. When asked later to resume office, he allegedly replied, ‘If only you could see the vegetables planted by my own hand … you’d never think of asking such a thing.’
Beginnings of the Christian Empire:
The Reign of Constantine
(AD 305–337)
Even as Diocletian set off on the long journey that would end at his retirement palace, and Maximian retired to a villa outside Rome, the succession plan began to fall apart. The reason was simple: although Constantius was now senior Augustus, he was far from content in his new role. He also saw a way to take advantage of new administrative structures that came into force just as he acceded to the highest office.
Although the Tetrarchic system established four separate imperial courts, under Diocletian the empire was not formally divided into administrative districts. The likely reason for this was that an informal arrangement was deemed perfectly adequate in a situation where no one challenged Diocletian’s authority over the empire as a whole. Now, as a result of the tensions surrounding the succession, the empire was split into four praetorian prefectures, with each prefect controlling three dioceses. Each of these was under the control of a vicarius – so called because the office-holder acted ‘in lieu of’ (vice) the praetorian prefect for the purposes of day-to-day administration.
Sowing the seeds of destruction
Under this new administrative system, Galerius and his prefect administered the three dioceses comprising the Balkan provinces, Maximinus ruled the three from the Dardanelles to Egypt, Severus controlled Italy, Africa and Spain, while Constantius held sway in Gaul and Britain. All of them, theoretically at least, were subordinate to Constantius. The four prefectures roughly mirrored the natural tax distribution zones of the second-century empire, with one major exception: the inclusion of Egypt with the east rather than with Italy marked a significant redistribution of resources towards Syria and the new capital district in northern Turkey. This is not to say that Rome did not still get grain from Egypt, and was not still a major market for the trade in luxury goods from the Far East via Egypt, but it did signify that other areas had grown in importance. The administrative joining of Egypt to the east reflects the fact that the natural economic and cultural divisions of the empire were beginning to shape the formal administrative structure in ways that would, in the long run, contribute to the downfall of the empire in the west.
However, any idea of the collapse of the western empire – or any inkling that the empire was now less than a century away from permanent division and partial occupation of its territories by barbarians – would have been far from the minds of Diocletian’s successors. There was no shortage of more immediate concerns to occupy them. No sooner had he come to power as the western Augustus than Constantius demanded the return of his son Constantine, who was effectively a hostage at the court of Galerius. He had other children, several of them boys, but they were all young, and it seems that the offspring of his early marriage with Helena held a special place in his affections. Constantius now had firm designs on his oldest son becoming emperor. Even if Galerius had guessed his colleague’s intentions, he was in no position to refuse him. Since Maxentius had been handed back to Maximian,
there was no justification for keeping Constantine from his father. And so, having secured the return of his son by the end of AD 305, Constantius left to campaign in northern England. On 25 July, AD 306, he died at York, and, evidently at his behest, the army declared Constantine emperor.
Galerius was furious, but was powerless to act, especially since Maxentius, inspired by developments in Britain, claimed the throne in Rome. His father Maximian came out of retirement to support him, and when Severus tried to quell the revolt he found that the loyalty of the army, which had served for years under Maximian, was suspect. Before the end of the year, he was imprisoned in a villa near Rome, and subsequently killed. Both factions now courted Constantine, who was recognized as Caesar by Galerius even as he contracted a formal marriage with Maximian’s prepubescent daughter, Fausta (as she was still a child, marital relations were postponed for the better part of a decade).
The empire fragments
In the summer of AD 307 Galerius invaded Italy. Constantine remained formally neutral, which probably guaranteed the failure of the expedition. With the limited forces at his disposal, and Constantine the only potential source of reinforcements, Galerius simply did not have enough manpower to lay siege to the capital (now surrounded by Aurelian’s massive defensive wall). Maximian, who plainly anticipated this turn of events, refused to engage in open battle. Faced with an impossible siege and a shortage of supplies, Galerius was forced to withdraw. The fact that he got out of Italy alive is testimony both to his own force of character and to the loyalty of the troops he had led for many years in the Balkans. It also testified to the fact that Diocletian’s reforms had only reinforced the tendency for the Roman army to divide along regional lines. This had occurred once before, in AD 193 – in the power struggle following the death of Commodus – and now it was patently obvious that the four main armies were essentially separate entities. The paradox of Diocletian’s reforms was that, while he sought to concentrate all power in the college of emperors, he actually succeeded in creating a number of separate governments that could operate independently of one another. Diocletian’s dominant personality had held the system together, and it is significant that, in the wake of his failure to defeat Maxentius, Galerius turned again to his mentor for help.